Estimation of a preference based single index from the sexual quality of life questionnaire (SQOL) using ordinal data

There is increasing interest in using ordinal methods to estimate cardinal values for health states to calculate quality adjusted life years. This paper reports the estimation of models of rank data and discrete choice experiment (DCE) data to derive a preference-based index from a condition specific measure relating to sexual health and to compare the results to values generated from time trade-off valuation (TTO). The DCE data were analysed using a random effects probit model and the DCE predicted values were rescaled according to the highest and lowest predicted TTO values corresponding to the best and worst SQOL health states respectively. The rank data were analysed using a rank ordered logit model and re-scaled using two alternative methods. Firstly, re-scaling the rank predicted values using identical methods to those employed for DCE and secondly, re-scaling the rank model coefficients by dividing each level coefficient by the coefficient relating to death. The study raises some important issues about the use of ordinal data to produce cardinal health state valuations

Estimation of a preference based single index from the sexual quality of life questionnaire (SQOL) using ordinal data

There is increasing interest in using ordinal methods to estimate cardinal values for health states to calculate quality adjusted life years. This paper reports the estimation of models of rank data and discrete choice experiment (DCE) data to derive a preference-based index from a condition specific measure relating to sexual health and to compare the results to values generated from time trade-off valuation (TTO). The DCE data were analysed using a random effects probit model and the DCE predicted values were rescaled according to the highest and lowest predicted TTO values corresponding to the best and worst SQOL health states respectively. The rank data were analysed using a rank ordered logit model and re-scaled using two alternative methods. Firstly, re-scaling the rank predicted values using identical methods to those employed for DCE and secondly, re-scaling the rank model coefficients by dividing each level coefficient by the coefficient relating to death. The study raises some important issues about the use of ordinal data to produce cardinal health state valuations.sexual health, quality of life, preference-based measures

Estimation of a preference based single index from the sexual quality of life questionnaire (SQOL) using ordinal data

There is increasing interest in using ordinal methods to estimate cardinal values for health states to calculate quality adjusted life years. This paper reports the estimation of models of rank data and discrete choice experiment (DCE) data to derive a preference-based index from a condition specific measure relating to sexual health and to compare the results to values generated from time trade-off valuation (TTO). The DCE data were analysed using a random effects probit model and the DCE predicted values were rescaled according to the highest and lowest predicted TTO values corresponding to the best and worst SQOL health states respectively. The rank data were analysed using a rank ordered logit model and re-scaled using two alternative methods. Firstly, re-scaling the rank predicted values using identical methods to those employed for DCE and secondly, re-scaling the rank model coefficients by dividing each level coefficient by the coefficient relating to death. The study raises some important issues about the use of ordinal data to produce cardinal health state valuations

Modelling childhood exposure to indoor air pollution across socio-economic groups

Population exposure to indoor air pollution may be modified by socio-economic factors in a number of ways, but such factors are rarely considered in indoor air quality models. Here, we present a model which estimates exposure to indoor PM2.5 across income groups for the Greater London childhood population. The model uses a national time-activity database, which gives the percentage of each population group in different residential and non-residential microenvironments and links this to simulated domestic indoor concentrations from the building physics model, EnergyPlus, and for non-residential microenvironments to a mass-balance model with empirically measured building air change rates selected according to a probabilistic approach. The results display distributions of exposure across income groups for children in London, where median daily exposure is 14.4 ug/m3 for children in the lowest income quintile versus 11.7 ug/m3 for those in the highest income quintile

Improving indoor thermal comfort, air quality and the health of older adults through environmental policies in London

In this work we evaluate the potential of selected environmental strategies in reducing air pollution and summertime indoor overheating. Associated changes in mortality rates are also calculated for older adults in London. Reducing these risks for vulnerable groups is an immediate priority and given that seniors spend most of their time indoors, our focus is on strategies that prioritize the transformation of residential environments for indoor thermal comfort and air quality improvements. For each strategy, we develop specific scenarios related to building adaptations and test potential reductions on indoor overheating and pollutant exposures from outdoor sources (PM2.5), as well as on senior mortality through the CRAFT tool (Cities Rapid Assessment Framework for Transformation). We then pick the scenarios with highest impacts on mortality, aiming to formulate effective policy recommendations for Greater London. Preliminary results suggest that environmental policies related to the installation of shading could have the highest reduction in heat and pollution-related senior mortality, followed by moderate effects due to building insulation retrofits and the greening of roofs. With an increasing ageing population in the UK and beyond, our work highlights the need for city-level policies to address building modifications, considering the importance of indoor spaces for older adults

Home Energy Efficiency and Subjective Health in Greater London

The UK has introduced legislation that requires net-zero greenhouse gas emissions to be achieved by 2050. Improving the energy efficiency of homes is a key objective to help reach this target, and the UK government's Clean Growth Strategy aims to get many homes up to an Energy Performance Certificate (EPC) Band of C by 2035. The relationship between home energy-efficiency and occupant health and wellbeing remains an area of ongoing research. This paper explores the nexus between home energy efficiency, energy consumption and self-reported health-an indicator of the general health and wellbeing of the population. We focus on Greater London through secondary data analysis. Energy-efficiency ratings and air infiltration rates of dwellings, derived from EPCs, were aggregated and matched to local area self-reported health and energy consumption data obtained from the Greater London Authority's (GLA) Lower Layer Super Output Area (LSOA) Atlas database. Our regression model indicates that improving the energy efficiency (SAP) rating by 10 points for a typical home may reduce household gas consumption by around 7% (95% CIs: 2%, 14%). Beta regression finds a positive, but not statistically significant association between median SAP rating and the proportion of the population reporting 'good or very good' health when considering all Greater London LSOAs (z score = 0.60, p value = 0.55). A statistically significant positive association is observed however when repeating the analysis for the lowest income quartile LSOAs (z score = 2.03, p value = 0.04). This indicates that the least well-off may benefit most from home energy efficiency programs. A statistically significant positive association is also observed for the relationship between self-reported health and air infiltration rates (z score = 2.62, p value = 0.01). The findings support existing evidence for the predominantly naturally ventilated UK housing stock, suggesting that home energy efficiency measures provide a co-benefit for occupant health provided that adequate air exchange is maintained

Anisotropy and controllable band structure in supra-wavelength polaritonic metasurfaces

In this letter we exploit the extended coherence length of mixed plasmon/exciton states to generate active metasurfaces. For this purpose, periodic stripes of organic dye are deposited on a continuous silver film. Typical metasurface effects, such as effective behavior and geometry sensitivity, are measured for periods exceeding the polaritonic wavelength by more than one order of magnitude. By adjusting the metasurface geometry, anisotropy, modified band structure and unidimensional polaritons are computationally simulated and experimentally observed in reflectometry as well as in emission.Comment: 4 figures, 1 Supplementary Material

Exposure to indoor air pollution across socio-economic groups: A review of the literature and a modelling methodology

Disparities in outdoor air pollution exposure between populations of different socio-economic status is a growing area of research, widely explored in environmental health literature. However, in developed countries, around 80% of time is spent indoors, meaning indoor air pollution may be a better proxy for personal exposure. Building characteristics and occupant behaviour mean indoor air pollution may also vary across socio-economic groups, leading to health inequalities. Following the results of a review carried out into indoor air pollution disparities, we incorporate socio-economic information into an indoor air quality model in order to evaluate exposure disparities in the indoor environment. The building physics tool EnergyPlus was used to model the effect of two policy interventions on indoor exposure to PM2.5 in two socio-economically different populations. Results suggest that households of low socio-economic status may be disproportionately affected by building and/or environmental policies which are implemented without consideration of the wider socio-economic processes governing the space